Maintenance-free lead-acid batteries are composed of positive and negative plates, separators and electrolytes, battery slots and connecting bars (or lead parts), terminals and exhaust valves.

1. The main parts of the battery

1. The pole plate is the core component of the battery, equivalent to the "heart" of the battery, which is divided into a positive plate and a negative plate.

2. The function of the separator is to isolate the positive and negative plates to prevent short circuits, which can be called "the third electrode". As a carrier of electrolyte, it can absorb a large amount of electrolyte and play a role in good ion diffusion (ion conduction). For sealed maintenance-free batteries, the separator can also be used as a "channel" for the positive plate to generate oxygen to reach the negative plate, so that the plate can smoothly establish oxygen circulation and reduce water loss. The key to the maintenance-free partition battery is the use of ultra-fine glass fibers.

3. Most of the electrolyte is composed of pure water and sulfuric acid, mixed with some additives.

The main function of the electrolyte lies in two aspects: one is to participate in the electrochemical reaction, which is one of the active substances of the battery; the other is to conduct electricity. make the chemical reaction proceed smoothly.

4. The safety valve is one of the key components of maintenance-free lead-acid batteries. It is located on the top of the battery. It plays a role in four aspects:

(1) Safety function, that is, when the gas pressure generated inside the battery reaches the pressure of the safety valve, open the valve to release the pressure to prevent production

(2) Sealing function, when the internal pressure of the battery is lower than the closing pressure of the safety valve, the safety valve is closed to prevent the leakage of the internal gas acid mist, and also prevent the air from entering the battery and causing adverse effects.

(3) Ensure the normal internal pressure of maintenance-free lead-acid batteries, promote oxygen recombination in the battery, and reduce water loss.

(4) Explosion-proof effect, some safety valves are equipped with anti-acid and anti-riot sheets. Such as Panasonic batteries.

In addition, there are many types of safety valve structures, mainly cap, umbrella, sheet and so on. It is common to make cap-type rafts from rubber with better elasticity. Its structure is simple and the failure rate is low, so it is widely used.